The program at the Children's Cancer Research Center (CCRC) in the past encompassed a multifaceted approach to the problems of pediatric oncology. This program project now focuses sharply on one of these problems: the biology of neuroblastoma, studied at the molecular level. Program laboratory and clinical scientists have developed considerable expertise with this neoplasm through many years of collaboration. We now wish to continue and extend this work through four interlacing laboratory projects which build on results obtained during past grant years. All of them, in turn, derive strength from an outstanding clinical base and access to the University of Pennsylvania Cell Center which therefore serve as core resources. The four projects concern (1) myc oncogene products: structure and function in neuroblastoma; (2) membrane glycoproteins specific to neuroblastoma; (3) molecular bases of the immune response to neural antigens: expression, modulation, and function of HLA-A,B,C in neuroblastoma; and (4) cell surface markers of metastatic neuroblastoma in relation to autologous marrow transplantation. These studies seek to determine the molecular bases for transformation of normal neural cells to their malignant counterparts, and the relationship of these events to the observed behavior of the neuroblastoma cell. Our studies also seek means of exploiting for clinical use the laboratory observations made by program participants, so that more children with this neoplasm can be cured. (IB)